Conventionally, selective call receivers, including pagers, have been packaged in a plastic housing with an attached belt clip. The belt clip is generally attached to the user's belt and thus exposed to various environments; therefore, it typically is designed to withstand excessive wear conditions. Pivotably attaching the belt clip to the pager by a pin is the most common method of attachement. Mechanical springs are used to exert force, provide flexibility, and store or absorb energy. Furthermore, a spring typically is coupled between the belt clip and pager for providing a clamping force between the belt clip and pager housing. The spring can be formed in any one of a number of configurations.
Generally, both the housing and the belt clip are molded of a durable plastic. A spring is inserted between the pager housing and belt clip to provide a constant clamping force. A pin is commonly used to hold the belt clip and housing together.
To open the belt clip assembly force is applied to the mounted end of the belt clip. The applied force must be greater than the clamping force. Typical belt clip configurations result in clamping forces which are less than those required to hold the clip open. Therefore, increasing the clamping forces will correspondingly increase the forces required to open the belt clip. This type of belt clip will be referred to as an increasing force belt clip. Since greater force is required to fully open the belt clip than to partially open it, the user is likely to open the belt clip just enough to clear the an object. This results in the belt clip being forced on and off of objects, which may damage the belt clip assembly or the attached object. Damage to the belt clip assembly generally requires replacing the pager housing and belt clip assembly.
Known belt clips utilize two basic, retaining pin designs. The first design comprises a roll pin, which is relatively crude in its manufacture when compared to machined pins; however, roll pins are low in cost. Typically, the belt clip and housing are manufactured from plastic and each have two supports molded on the outer surface such that the pin can be inserted to hold the entire configuration together. The roll pin is force fit into the holes of the supports for an interference fit, resulting in a constant stress that holds the belt clip and housing together. The roll pin usually places stresses on the plastic supports that may exceed the plastic's allowable stress. When this occurs, the housing support will yield making the belt clip assembly inoperable. This type of failure is not repairable because of the forces exerted by the spring; therefore, the housing assembly must be replaced which inconveniences the user.
The second pin design comprises a machined, clevis pin secured by an E-ring or other suitable latching mechanism. The machined pin generally does not result in damage to the product, however, the machined pin is relatively expensive.
Thus, what is needed is an improved apparatus for pivotably attaching a belt clip to a selective call receiver.